Ultrasonic endoscopes that can perform both endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound-guided fine needle aspiration (FNA) have been proposed. Ultrasonic endoscopes of this type are each provided with, in a rigid distal end portion located at the distal end of an insertion portion to be inserted into the body, a side-viewing optical observation portion, an ultrasonic probe, and an opening of a treatment tool conduit (instrument channel). Flexible linear treatment tools such as a puncture needle and a contrast tube are selected based on a treatment to be executed, and are inserted into the treatment tool conduit to protrude from the opening. An elevator for changing the direction in which the flexible linear treatment tools protrude is provided in the opening of the treatment tool conduit.